All my handhelds are black.And I have a DS lite,DSi,and a 3DS. And I always get them when they are pretty much 2 available colors (except for my DS lite).It just seems to be a great color for a handheld,and for other things to since black has been all the rage lol.
But yeah,Either You get Black or White,Shade or Tint....white is a bright color,but you might want all your handhelds to be a unique color so you could get a black 3DS.